James Cook University researchers will be part of a team working to combat Australia’s chronic soil infertility problem with a technique involving sowing paddocks with crushed rock.
Associate Professor Paul Nelson is a soil scientist at JCU. He said Australia’s soils are generally highly weathered and infertile, which constrains crop production and carbon storage.
“Our best soils, which are quite scarce, are developed on basalt, so our project will take crushed basalt – a by-product of gravel manufacture – and apply it to soil. This is a way of making poor soils more like those good soils,” said Dr Nelson.
“By applying the extra basalt we’re giving nature a boost. The process neutralises soil acidity, it also releases nutrients such as calcium, magnesium, phosphorus and potassium.”
He said the project will improve soils but also aims to lock up carbon, as carbon dioxide dissolved in soil water can react with the basalt.
“This involves the carbon solidifying in the soil as carbonate or leaching to groundwater, rivers and the sea, where it is stored long-term. Modelling has indicated high rates of carbon capture are possible,” said Dr Nelson.
Tropical North Queensland Drought Hub Director, Professor David Phelps said the hub is extremely pleased to have helped deliver the funding to such a promising carbon sequestration project.
“Projects like this have multiple benefits including building soil health and resilience, reductions in fertiliser use and reducing farmers costs. We will provide continuing support to help build our regions adaptability to climate variability,” said Professor Phelps.
With the help of $4.8 million funding from the Department of Agriculture, Fisheries and Forestry, field trials will be carried out on seven farms over four years to assess the effect of the process, known as enhanced rock weathering, on crop productivity, soil health and carbon sequestration.
“We aim to help farmers improve the environmental sustainability of their operations and alleviate Australia’s chronic soil infertility and help Australia reach our Net Zero target,” said Professor Nelson.
JCU will conduct the trial in partnership with the Tropical North Queensland Drought Hub, UniSA and Carbonaught.
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